Gut Feeling

“In a study by Cryan and colleagues, a fecal microbiota transplantation from depressed human patients to GF rats resulted in behavioral and physiological symptoms of depression in the animals. “In effect, we were able to transfer the blues,” says Cryan. “Experiments like this are helping us move away from just describing changes and toward causative effects.”

The animal evidence seems promising, but translating this treatment to humans is still in the very early stages. OpenBiome, a nonprofit stool bank based in Cambridge, Massachusetts, is planning the first trials of fecal microbiota transplants for depressed patients. “We will try to select a donor that would complement the deficiency or replenish those bacterial communities that are depleted in patients with depression,” says Shrish Budree, senior clinical research scientist at OpenBiome (Figure 4, right). “One great aspect of OpenBiome is that we highly characterize all our stool donors,” Burdree notes. “They go through a rigorous clinical and serological screening, and we also genetically sequence all our donors so we know the exact microbial composition of their stool. If we know that certain bacterial communities are abnormal in a recipient, we can select a donor who is enriched in those bacteria.”